I blew my amp I think

I own(ed) a Crate Bx-80 (I know they don't manufacture this amp any longer) and I seem to have blown it someway. I took the top of the amp apart to see that the circuitboard has been blown. I think the speaker (a 15") is still good. Is there anyway I could get this fixed or is it time for a new amp?

Well, I can turn it on and it powers on, but when i plug in a cord I dont get the usual buzz sound. I can take a picture of the circuitboard part that is blown if you want to see it. The amp was working perfectly like a month ago.

Originally posted by ergodynebass I can take a picture of the circuitboard part that is blown if you want to see it. The amp was working perfectly like a month ago.

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Oh, so you can actually SEE that the circuitboard is bad. Crate is a crappy amp anyway. Perhaps it is time to get a another bass amp. Seems like your amp has done it's duty and just died of old age....as taps is hauntly heard in the distance....

Yes, Crates are horrible, I just had it for practicing (which is mainly what I use all my amps for). The thing I hate is I paid 200 dollars for it used and it didn't even last me a year. I guess this time I should maybe buy a amp new with a warranty. You have any suggestions on a 100-120watt amp that ranges between $400-500. I would prefer Ampeg, SWR, or Hartke.

One thing to think about is that Crate amps come with a 5 year transferrable warranty. If the seller didn't give you the original sales receipt, then you might wanna go ask for it (assuming that the amp is under 5 years old, that is). It may very well still be under warranty. Personally, I don't think that Crates (the newer ones at least) are horrible at all - no, they're certainly not Eden or SWR, but you do get more than you pay for with them.

In the $400-$500 range you should be able to get a SWR Workingman's 10 (perhaps the 12), or a Ampeg B100 (I think that's the right model number), and I think that you could probably get one of the Hartke Kickback models in that price range too. Shop around and see what you can find - and don't forget to check out used, just make sure that you try before you buy.

I bought it off of daddy's used gear (www.daddys.com) because I didn't have much money, I don't think they have the receipt for it and anyways, I don't think Crate will do the warranty for a model they don't manufacture anymore (they might though).

Mujibubga,

Yes Ampeg makes Crate products, I just think Ampeg is more reliable than Crate.

Yes, It is just a small part that looks burnt near the input plugs. I was thinking about getting it repaired but there's not that many amp repairers around here and not that many that fix Crate, I might try though.

I'll take a picture of it in a few minutes, its like right behind the input jacks, there are 2 of them. That might not be the problem, but it looks like it to me. I mean, it gets power to the amp and you can hear the pop noise from the speaker when you turn the amp on but there is no buzz from the end of the cord signifing that I have a good connection.

The spots not that big but I really didn't want to waste time lugging this to a repair shop when in actuality the amp is a peice of crap ever since I bought it. I do like 15" speakers though. How much do you think it would cost to get this fixed?

Tight to the left of the uppermost white strip is what appears to be a small power resistor. The burning sort-of follows the outline of the resistor: it makes a 'bulge' around it.

This burning, whilst not ideal, is not at all unusual on PCBs. Over time, the (in this case) resistor heats and it scortches the board.

I suspect the resistor is there to drop the higher power rail voltage in the amp (say, +- 40-ish Volts) to something more managable for the preamp circuits. (Your pic is clearly the preamp side with the input jacks @ top left). There will almost certainly be a regulating diode (Zener) with some smoothing - the blue tubular things - associated with this dropper resistor.

Without having seen the amp - and, of course with 3000+ miles between us - I'm not convinced that the burning is your problem: it might be, but I'm not convinced.

Sorry but I've absolutely no idea what it would cost to fix. I could image, what, $50 to $100 depending upon exactly what's wrong.

Just a thought but what happens when you switch the amp on. Do the lights come on or is it completely dead? Does it smell as though there's been a recent "fire" on the PCB? But, as I said @ first, what do the white strips do?

I have no idea what these white strips do but the light comes on when you turn the power on. The white strip reads "COLBER 220 Ohm 10% CW10A", maybe that will give you an idea. Sounds like a resistor or something to me.

Bob Lee (QSC)In case you missed it, I work for QSC Audio!Commercial User

The "white strips" are resistors, ones that are meant to dissipate at least several watts. The one that has the charred area underneath probably is dissipating too much power, causing it to get too hot. A short circuit somewhere in its adjacent circuitry might be the culprit, causing too much current to flow through the resistor. If the board gets too burned, it'll be too damaged to repair.

It doesn't look too bad yet, so at any rate, you can probably get it fixed. I'm guessing that a 220-ohm 10-watt-or-whatever resistor is probably for dropping a higher DC supply rail voltage down to a lower voltage, perhaps for the ICs visible in the photo. Maybe one of the ICs is blown and shorting one of its supply rails to ground or nearly to ground. It probably wouldn't be too expensive, but you might as well contact Crate to see if it's under warranty. Maybe they can verify the warranty by the amp's serial number.

Crate amps might not be the greatest, but they aren't bad, either. My practice amp is a BX-25, and when I was trying out amps, it handled the low B on a 5-string much better than some comparably-sized amps bearing some more prestigious names did.